The present invention relates to a monitoring apparatus for monitoring a band-shaped object running continuously and, more particularly, to a monitoring apparatus for monitoring the flow of paper in, for example, a paper machine.
For a conventional paper machine, an operator performs monitoring while roving periodically during the operation to check the conditions of operation, by which the stable operation of the machine is achieved. To detect the occurrence of paper cut, a paper cut detecting sensor, which consists, for example, of an infrared irradiator disposed on the outer side of a running paper and a detector disposed on the inner side of the running paper, is installed on the machine. When the paper is cut, the detector detects the infrared rays, by which paper cut is recognized.
With such a paper cut detecting sensor, although paper cuts can be found, the cause for the paper cut cannot be known. For this reason, in recent years, paper conditions are monitored by installing a camera and a light source, and also the conditions are recorded on a video cassette recorder or a digital memory and the state of paper breakage is replayed. Thus, the operator can understand the cause for paper cut.
However, with this method, the recorded scene showing the state of paper cut is only replayed, but paper breakage (paper cut) cannot be prevented.
The present invention has been made in view of the above situation, and accordingly an object thereof is to provide a monitoring apparatus that prevents abnormal running of paper by detecting the abnormal running, and also prevents paper breakage. Further, another object of the present invention is to prevent abnormal running of a band-shaped object running continuously.
To achieve the above objects, the present invention provides a monitoring apparatus in which light from a light source is caused to penetrate a band-shaped object running continuously, the object is photographed by using the transmitted light, and the image is processed, by which a change amount relating to the running path of the object is quantitatively monitored.
The present invention can be applied to a case where a place where paper is easily broken is monitored on, for example, a paper machine. That is to say, light from a light source is caused to penetrate a running paper in the paper machine, the running paper is photographed by using the transmitted light, and the image is processed, by which the change amount of separation point where the running paper separates from a roll is monitored quantitatively to diagnose a trouble of the paper machine.
The monitoring apparatus in accordance with the present invention comprises light emitting means for causing light to fall on a paper run by rolls in the paper machine, photographing means for photographing the light penetrating the paper from the light emitting means, image processing means for processing the image of the photographing means, and diagnosis means for diagnosing a trouble of the paper machine by quantitatively monitoring the change amount of separation point from the roll based on the processing results of the image processing means.
In particular, the present invention can be applied even to a case where the photographing environment of the portion to be monitored is deteriorated, for example, by the occurrence of mist. In this case, as the light source of the light emitting means, a metal halide lamp is preferably used.
It is preferable that the trouble diagnosis conditions be set in advance based on the change amount of the object at the normal time. When the trouble diagnosis conditions are influenced by various environmental conditions, it is preferable that the trouble diagnosis conditions be changed with the change in the environmental condition. For example, the conditions for diagnosing a trouble in the diagnosis means should be made capable of being changed according to the basis weight and draw amount of paper.
When machine is judged to have a trouble, a configuration for automatic control for making the machine operation normal is most preferable. Specifically, when a trouble is diagnosed, paper cut is prevented by further providing control means for controlling the draw amount according to the result of diagnosis.
The photographing with the photographing means should preferably be performed by a plurality of cameras by dividing the photographing region (portion to be monitored). Specifically, each region provided by dividing the portion to be monitored should be photographed by a different camera. Also, the processing in the image processing means should be performed with a plurality of images obtained by photographing the different regions.
When the object is a paper (running wet paper) of a paper machine, and the state of the paper is monitored, the most preferable configuration is such that
(1) the photographing direction of camera and the position of light source are in an opposite positional relationship with respect to the paper,
(2) in the image processing, the change amount of separation point, which is a point where the paper separates from the roll, is monitored quantitatively to diagnose a trouble of the machine,
(3) the trouble diagnosis conditions are changed according to the basis weight and draw amount of paper, and
(4) the draw amount is automatically controlled according to the result of trouble diagnosis to prevent paper cut.
The basis weight in this specification is a weight per one sheet of paper of 1 m2. The draw amount is the degree of tension of web between the parts of the paper machine, and is determined by the difference in speed between the driving rolls of the sections of the paper machine.
As is apparent from the above description, the present invention achieves the effects described below.
In the present invention, light from a light source is caused to penetrate a band-shaped object running continuously, the object is photographed by using the transmitted light, and the image is processed, by which a change amount relating to the running path of the object is quantitatively monitored. Therefore, the change in running of the object can always be grasped, so that accurate monitoring can be performed.
Also, the monitoring apparatus in accordance with the present invention comprises light emitting means for causing light to fall on a paper run by rolls in a paper machine, photographing means for photographing the light penetrating the paper from the light emitting means, image processing means for processing the image of the photographing means, and diagnosis means for diagnosing a trouble of the paper machine by quantitatively monitoring the change amount of separation point from the roll based on the processing results of the image processing means. Therefore, the change in running of the object can always be grasped, so that accurate monitoring can be performed.
If a metal halide lamp is used as the light source of the light emitting means, the separation from the peripheral equipment can be made well in the image processing, so that accurate monitoring can be performed even when the photographing environment is adverse.
If the trouble diagnosis conditions are made capable of being changed according to the basis weight and draw amount of paper in the diagnosis means, the diagnosis accuracy is improved, and most preferable monitoring can be performed.
If controlling means is further provided to control the draw amount according to the diagnosis result when a trouble is diagnosed, paper cut can be prevented by correcting the shape of profile, and a press part etc. can be controlled.
If the configuration is such that the photographing with the photographing means is performed by different cameras for regions provided by dividing the portion to be monitored, and the processing in the image processing means is performed with a plurality of images obtained by photographing the different regions, the effect of the photographing environment can further be reduced, and the change in the object or the running paper can be grasped exactly, so that more accurate monitoring can be performed.